This study is planned as the first in a series of studies designed to investigate the effects of expertise and age on certain cognitive resources relevant to mental workload capacity of pilots engaged in simulated aviation (flying) tasks. A secondary task workload assessment methodology will be used in this study, with a PC-based flying task with different levels of workload demand constituting the primary task, and a Sternberg choice reaction time task with two levels of memory load as the secondary task. A mixed design using repeated measures will be used, with age and expertise as between-subjects factors, and primary task workload and secondary task memory load as within-subjects factors. Groups of old (age 60 and above) and young (age 30 and below) pilots, with those in each group having various levels of expertise (as defined by number of flight hours) will serve as subjects. Two major hypotheses for this study are: l) increases in primary task workload will have adverse effects on secondary task performance, but that these adverse effects will be greater for the older pilots; and 2) if aviation tasks can be considered a specific task domain, then expertise may reduce these age differences as primary task workload increases. Implications of potential results are discussed, and directions for future research concerning extending this methodology to study the effects of expertise and age on other cognitive resources relevant to mental workload capacity are presented.